Strap sealing tool



' Filed Oct. 6, 1958 May 15, 1962 i J. v. NovAK ETAL. 3,034,384

STRAP SEALING TooL 2 Sheets-Sheet 1 62 6 INVENToRs:

FO JOHN V. NOVAK MARCHAND B. HALL BY 44 @M7/@ @@W'f Z6 FLP.: E.

May 15, 1962 J. v. NVAK ETAL 3,034,384

STRAP SEALING TOOL Filed oct. s, 195s 2 sheets-sheet 2 n2 22 "'f/ E4 JNVENToRs: JoHN v. NovAK MARCHAND B. HALLl BY l @MM (7% ,5.

tarea This invention relates to improvements in strap sealing tools for use in forming joints between the overlapping ends of metal straps of the kind often employed to secure and to reinforce packages or boxes, or to bind together a group of cargo units in the loading of freight cars and other carriers.

According to well known practice, the ends of a metal strap are overlapped within a tubular seal and, after the strap has been drawn taut around the object to be reinforced, a sealing tool is operated to deform the seal and the overlapping strap ends therein to provide an interlocking joint. It sometimes happens, however, that the sealing tool is not fully operated during the deformation of the seal so that an incomplete joint is formed. Later, when the joint is subjected to severe strains, an incomplete joint of this kind may fail to the extent that the strap ends may be pulled apart, thereby causing damage and injury.

Certain strap sealing tools heretofore have been devised which include in their constructions, means for preventing removal of the tool from a seal once deformation of the seal has been begun, until complete deformation of the seal has been accomplished. This, of course, insures that a complete joint forming operation will be carried out each time the tool is actuated for that purpose. Prior tools of this character are shown and claimed in United States Letters Patent, Nos. 2,831,380, 2,832,243 and 2,833,170, and in the copending application of John J. Pachter, Serial No. 488,543, filed February 16, 1955, now Patent No. 2,868,048. Although entirely satisfactory for their intended purposes, these prior tools, in general, have been relatively complicated and expensive of construction, and the mechanisms therein for insuring the complete formation of a joint have been built as integral parts of the tools and have not been such as to permit their easy addition or adaptation to existing tools. Thus, one of the important objects of the present invention is to provide an improved strap sealing tool that is relatively more simple and easier to construct than the prior tools, but which is so constructed that a complete joint forming operation must be completed each time a joint forming movement is initiated.

Another object of the invention is to provide a strap sealing tool having joint forming parts actuated by relatively movable lever arms in combination with means carried by one of the movable lever arms for preventing the release of the tool from the joint until the relative movement of the lever arms has been carried out to the extent required to produce a complete joint.

Yet another object of the invention is to provide a strap sealing tool having joint `forming parts actuated by relatively movable lever arms, in combination with means for preventing the release of the tool from the joint until the relative movement of the lever arms has been carried out to the extent required to produce a complete joint, wherein the release preventing means is relatively simple and inexpensive to manufacture and can be readily adapted to existing strap sealing tools.

Still another object of the invention is to provide a strap sealing tool having a head including joint forming parts actuated by relatively movable lever arms, in combination with means for preventing the releasev of the tool from the joint until the relative movement of the lever arms has produced a complete joint, wherein the release ent preventing means is structurally independent of the joint forming parts.

A further object of the invention is to provide a strap sealing tool having joint lforming parts operated by relatively movable lever arms, in combination with means for insuring the completion of the movement of the lever arms when the first movement thereof has been initiated, wherein the completion insuring means can be easily adapted to a family of strap sealing tools and can be easily serviced.

A still further object of the invention is to provide a strap sealing tool having joint forming parts actuated by relatively movable lever arms, in combination with a latch mechanism carried by one of the lever arms and conlUolled by cam contours on the outside surface of the side plates of the tool whereby to insure the completion of the required movement of the lever arms after operation thereof has been initiated.

Other objects relate to various features of construction and arrangement of the parts which will appear more fully hereinafter.

v The nature of the invention will be understood from the following specification taken with the accompanying drawings in which one embodiment of the invention is illustrated. In the drawings: i

FIG. l shows a side elevation of one form of theimproved sealing tool in its closed position, with parts of the operating'levers being broken away;

FIG. 2 is a top plan view of the tool FIG. 1;

FIG. 3 is an end elevation of the tool as seen from the left of FIG. 1;

F1G. 4 is a view similar to FIG. 1, but showing certain portions broken away and other parts in section, and illustrating the relative position of the overlapping strap ends and the seal after having been fully deformed by the tool; Y

FIG. 5 is an enlarged fragmentary view, partly in section and with certain portions broken away, illustrating the operation of the latch mechanism of the tool, the parts being shown in a position permitting the operating lever arms to be moved to their fully opened position;

FIG. 6 is a view similar to FIG. 4, but showing the parts in a fully opened position to facilitate placement of the tool over a pair of overlapping strap ends and an associated seal;

FIG. 7 is a view similar to FIGS. 4 and ,6, but illustrating the position of the parts of the latch mechanism after the initiation of a joint forming movement of the lever arms, the latch parts being disposed so that the lever arms cannot be moved to permit disengagement of the tool from the partly formed joint; and

FIG. 8 is a perspective view of one type of strap joint that may be formed` by the sealing tool of the present mvention.

The strap joint shown in FIG. 8 comprises a metal strap of steel or the like having overlapping ends 10 and 12. which are enclosed by a surrounding tubular metal seal 14. The seal 14 initially is provided with straight side Walls forming a flat sleeve through which the strap ends 10 and 12 are threaded, after which the strap is drawn taut around the package or box, and the present sealing tool is then operated so as transversely to shear and to deform the lateral edges of the strap and the seal 14 to provide wing-like projects 16 having cooperating Yshoulders on portions of the seal 14 4and the enclosed strap ends 10-12 which interlock with each other, thus illustrated ift providing an interlocking joint; Instead of transverselyk shearing the lateral edge portions Vof the seal and thel strap ends to provide the wing-like portions 16, the lateral edges of the strap and the seal may be deformed to provide registering depressions that are characteristic of another well-known type of interlocking joint.

The tool shown in the drawings includes a head having cooperating relatively movable shearing and bending jaws which are operated by relatively movable lever arms after the tool has been placed in a position to embrace the seal and the overlapping str-ap ends. The tool, which is generally designated by the numeral 2i), comprises a pair of side plates 22 that are identical inV construction and which are connected to provide a frame on which are pivotally mounted two pairs of bending and shearing dies or jaws 24 which cooperate with aV pair of spaced apart anvils 26 also carried by the side plates 22. A pair of lever arms l28 and 39 is provided to operate the dies 24, the lever arm 28 being xedly secured between the `side plates l22 and the lever arm 30 being pivotally mounted between the side platesrand operatively connected to the dies 24 to cause joint forming movemen thereof. Y

Each of the side plates 22 is generally triangular in outline and has a generally Vstraight forward edge 32 joinedto a lower edge 34 that is adapted to be placed adjacent the bundle or article to be strapped. The lower edge 34 of each plate is provided with a generally rectangular recess 36 therein which receives the overlapping strap ends and the associated tubular seal and permits these partsto be placed in a convenient position to be acted upon by the diesV 24 and the anvils 26. The pair of bolts 38, provided with Alock nuts 40, extend through aligned apertures provided in the side plates 22 and in the adjacent end of the arm 28 for xedly securing the side plates upon the end of the lever arm28.

The anvils 26 are identical. Each is generally rectangular in form and iscarried against the inner surface of the associated side plate 22 adjacent the recess 36 `there-` in. Each anvil includes -a pair of shear surfaces 42 which extend diagonally inwardly and upwardly into the spaces defined by the recess 36 to provide spaced apart points of and the pills-44 are held in place by a retaining plate 46 Y mounted on the side plates 22'by a bolt 48 having a coop-v erating lock nut 50. e

VEach of thepins 44 also pivotallymonts a juxtaposed pair of dies 24, thedics 24 beingV disposed between the anvils 26 and each includingan 'arm 52 and a hooked extremity or jaw 54 provided withY an edge 56 adapted to cooperate with the .edge 42 -on the adjacent anvil 26 to provide the necessary shearing and bending action on the strap and the seal.Vv v l 'Ihetorce for moving the dies 24 is derived from the pivoted lever arm 30 which is operatively mounted between the side plates 22 upon a bolt 58 having a cooperating llock nut 60. Each pair of the dies 24 is provided with a link 62 which is curved downwardly and outwardly and is provided at one end with a bifurcated yoke 64 having a -pair of ears `66 disposed on either side of the associated pair of dies24 and pivotally connected thereto by a pin 68. Thefother ends of the Vlinks 62fare joined to the levei arm 30 by a Vpair of connectors 70 which have one end thereof received Vin recessesrin uthe sides of the lever arm 30 and pivotally vconnected thereto by a pinY 72.V The other ends ofthe connectors 72 fare'pivotally connectedrto the links 62 by a shaft 74which extends therethrough and through elongated slots 76 Vformedin .the side plates 22.

Ar`o1ler78 is provided on'each end of the shaft 74 and is adaptedtobe inalignment with and to engage'the edges of the slot 76 Yand is held in position bye-a nut .8,0 engaging a threaded portiony on' the associated end of the shaft74. W

p `Pivotal movement Yof the'lever Varm dit) away from the v ,lever Varm28,i.e.,in a counter-clockwise directionY yiewedin FIGS. vlanli, willmove the connector V70 and ,Y -the 62 inlaidirection awayY from theanvils 26 and thus serve to move the arms 52 of the dies 24 inwardly lfrom the anvils 26 and to open the dies -for the reception of a pair of overlapping strap ends and a seal therebetween. Conversely, movement of the pivoted lever arm 3? toward the lever arm 2S (in a clockwise direction as viewed in FIGS. l and 4) will move the connector 70 and the links 62 toward the anvils 26, pivoting the die arms 52 outwardly away from each other and thus causing the jaws 54 of the dies 24 to pivot toward each other and across the shear surfaces 42 of the anvils 26 in a shearing and bending movement with respectthereto. The dies 24 are shown in their fully opened position in FIG. 6, in the fully closed position in FIGS. l and 4, and in an intermediate position in FIG. 7.

When the shearing and bending dies 24 reach the position illustrated in FIG.V 7 of the drawings, the diesrwill have partially sheared and bent the loverlapping strap ends and the seal 16 to form a partial joint. This partial joint may -be suiciently formed to hold the ends of the strap together and perhaps may even be satisfactory under moderate stress conditions, but the joint is not fully `formed so as to enable the joint to withstand the full strains that the joint will encounter in actual use. It also is to be noted that when the dies 24 are in this intermediate position, it is impossible for the strapping tool 20 to be disengaged from the partially formed joint Without relative movementrof the lever arm 30 away from the lever arm 28 -to open the jaws ofthe dies 24.

Accordingly, there has been provided in the strapping tool of the present invention a stop latch mechanism which is effective, as soon as the joint is partially formed, to prevent relative opening movement of the lever arms 28 and 30 away from each other (and therefore simultaneously to prevent removal of the strapping tool 20 from the partially formed joint) until the operating parts of the tool have been moved through a complete joint forming cycle. Furthermore, the latch mechanism is so constructed that completion of the joint forming cycle of operation will automatically place the latch parts in a position permitting the lever arms then to be moved to disenga'ge the tool from the newly formed joint, after which the latch mechanism is again operated to place the parts in condition so that they will perforintheir stopping function when the next joint is partially formed.

The latch mechanism is generally designated by the numeral 9u (FIG. 4) and is mounted in the pivoted lever arm 30 and cooperates with pairs of cam surfaces formed on the third' edges of the side plates 22. The. lever arm 3) is formed of two parts and includes a solid terminal or inner end part 92, which is pivoted upon the pin 58 between the side plates 22, and ahollow cylindricalhandle part 94 which receives therein one end of the terminal part 92. The terminal part 92 is provided with anV opening or slot 916 therein which extends there-through transversely to the longitudinal axis of the handlerV and is L- shaped when viewed from the side, one leg of the slot being disposed transversely of the axis of the part 92 and the other leg of therslot 96 being disposed parallel to the e' longitudinal Vaxis of the part `92. Mounted rin this slot,

for shiftable movement from one leg thereof to the other, isa transversely extending latch pin 98` which is generally cylindrical in form but `which is slotted intermediate its ends to Aprovide a fiat surface V100 facing the outer end of `the handle 30. r[he ends V,ofi the latch member 98 extend lbeyond the sides of the Llever arm 30 and are .adapted to engage and, at times, to ride upon cam surfaces formed on the thirdedges of the side plates 22, all as will be described more vjiiully.hereinatten A movable plunger 102engages the fiat surface 100of the latch 4member 98, the .plunger .102 being mounted in a. cylindrical and longitudinally extending Vbore I04 within the lever-*arm 3.0'. A spring 106, under compression,

' is disposedbetween the plunger 102 and anadjustable longitudinally of the lever arm 30 against the latch member 98 whereby to urge the latch member 98 continually in a direction toward the inner end of the handle 30. Due to the engagement of the plunger 102 in a slot providing the flat surface 100 in the latch member 98, the latch member is free to slide across the contacting face 110 of the plunger 102 at the same time it is being spring urged thereby. The bore 104 is so positioned with respect to the slot 96 that the latch member 98 can be shifted across the face 110 of the plunger 102. Thus, the latch member 98 can move from one leg of the slot 96 to the other and back again ywhile in contact with the face 110- of the plunger 102.

Selected and controlled movement of the latch member 98 to give the desired operation of the strapping tool 20 is brought about by relative movement between the lever arms 28 and 30 in cooperation with cam surfaces for-med on the adjacent edges of the side plates 22. In one stable position of the latch member 98, it is positioned in the leg of the L-shaped slot 96 that is most remote fromthe pivot point of the lever arm 30, and when the latch member is so disposed it is held in that position by the plunger 102 (see FIGS. l, 4 and 5). With the parts in this particular position, the lever arm 30 may be pivoted with respect to the side plates 22 away from the lever arm 28 to the maximum extent, and more particularly from the position illustrated in FIG. 4 through the position illustrated in FIG. 5 `and to the position illustrated in FIG. 6. When the parts arrive at the position in which the lever arms 28 and 30 are at their maximum 'angular displacement with respect to each other, the outer ends of the latch member 98 engage a release abutment surface 112 provided on each of the side plates 22, this engagement serving to shift the latch member 98 from the leg of the slot 96 most remote from the pivot of the lever arm 30 to a position of general longitudinal alignment with the other leg of the slot 96. The latch member 98, however, is prevented from entering the other leg of the slot 96 due to the presence of cam surfaces 114 that are provided on each side plate 22 and which are shaped as a section of an arc of a circle, this position of the parts being illustrated in FIG. 6 of the drawings. Relative movement of the lever arms 28 and 30 toward each other will cause the latch member 98 to slide or ride along the cam surfaces 114 until it falls across abutment faces 116 and onto substantially straight cam surfaces 118 that are also provided on the plates 22. The parts will then be in the position illustrated in FlG. 7 of the drawings, the latch member 98 being disposed in the leg of the L-shaped slot 96 disposed nearest the pivot point of the lever arm 30, and the spring 106, through the plunger 102, holding the latch member 98 against the cam surfaces 118. The-abutment faces 116, in cooperation with the outwardly extending ends of the latch member 98, effectively prevent movement of the levers 28 and 38 away from each other after the parts assume the position wherein the latch member 98 enga-ges the abutment faces 116 (see the illustration of the position of the parts in FIG. 7 of the drawings). The engagement of the outer ends of the latch member 98 with the abutment faces 116 thus prevents the handle 30 from being returned to its initial or open position once it has been moved sufiiciently toward the closed position to cause the latch member 98 to pass the abutment faces 116.

Continued joint forming motion of the lever arms 28 and 30, i.e., movement toward each other, will cause the latch member 98 to ride along the cam surfaces 118 until it reaches angularly disposed reset cam surfaces 120 provided on the plates 22 at the lower ends of the cam surfaces 118. Due to the angle of the cam surfaces 118 with respect to the arc through which the slot 96 travels as the lever arm 30 is pivoted toward the other arm 28, it will be understood that the latch member 98 is raised within the longitudinal leg of the L-shaped slot 96 as the latch member rides along the cam surfaces 118 while the lever arm 30 is being moved from its position illustrated in FIG. 7 toward the fully closed position thereof shown in FIG. 4. At the time the latch member reaches the lower end of the cam surfaces 118, it will have been raised within the yslot 96 to the juncture of the two legs of the slot, whereupon forceful contact of the outer ends of the latch member against the reset cam surfaces 120 will slide the latch member across the contacting face of the spring pressed plunger 102 `and into the other leg of the L-shaped slot 96, as illustrated in FIG. 4, Where the latch member will thereafter clear the abutment faces 116 upon returning or opening movement of the lever arm 38. Thus, the completion of a full stroke by the lever arm 30 will automatically set the latch member 98 in a retracted position that will permit opening of the lever aim 30, with consequent opening of the jaws 54 of the tool permitting the tool to be removed from a completely deformed seal 14. During the opening movement of the arm 30, the latch member 98' will be maintained in its retracted position due to the urging of the spring i106 and the contact between the latch member 98 and the edge of the slot 96, until the latch member 98 again is brought into contact with the abutment faces 112 by movement of the lever arms 28 `and 30 to the maximum angular displacement from each other.

The manner in which the illustrated construction accomplishes the objectives of the present invention will now be described with reference to a typical joint forming operation. The free ends 10 and 12 of the steel strap are threaded into a seal 14 and the overlapping ends are pulled taut. The lever arms 28 and 30 of the strapping tool 20 are then moved away from each other to the position of maximum angular displacement, assuming that the parts are initially in the position illustrated in FIG. 5, otherwise full joint forming movement of the lever arms 28 and 30 must be had in order to place the latch mechanism 98 in the proper condition for full opening movement of the lever arms. As the lever arms 28 and 30 approach the point of maximum angular displacement -away from each other, the outwardly extending ends of the latch member 98 engage the abutment faces 112 of the side plates 22 whereby to shift the latch member 98 bodily across the face 110 of the plunger 102 and into alignment with the leg of the L-shaped slot 96 disposed nearest the pivot point of the lever arm 30. This opening movement of the lever arms 28 and 30 also pivots the dies 24 so that the hooked extremities or jaws 54 thereof are spaced farthest apart. The tool can then be placed over the overlapping strap ends 10 and 12 and the seal 14, as shown in FIG. 6 of the drawings. Next, the operator moves the lever arms 28 and 30' toward each other whereby to slide the latch member 98 along the part circular cam surfaces 114 until it drops across the stop surfaces 116. Such movement of the lever arms 28 and 30 also pivots the dies 24 so as to force the shear surfaces 56 thereof toward the anvils 26 and the shear surfaces 42 thereon. As a result, a partial shearing and bending of the seal 14 and the straps 10l and 12 is accomplished. This will place the parts in the position illustrated in FIG. 7 of the drawings.

The strapping tool 20 cannot be disengaged from the joint when the dies 24 are in such a partially closed position. The llatch member 98, acting against the stop surfaces 116, effectively prevents full opening movement or movement of the lever arms 28 and 30 away from each other whereby to permit disengagement. As a consequence, the operator has no alternative but to continue moving the lever :arms 28 and 30 towardeach other to complete the formation of a good and tight joint. The latch member 98 will not have its position effectively changed until it has been moved 'across the full length of the cam surfaces 118 and into engagement with the reset cam surfaces 120, this contact occurring only at the completion of the joint forming operation.

Contact -between the ends of the latch member 98 and the reset cam surfaces i129 will move the latch member formation of a joint when the operation of the tool has once been initiated with a seal and the enclosed overlapping strap ends positioned between the jaws which are initially separated from each other as shown in FIG. 6. In the operation of the tool, the lever arm 2S is conveniently held in one handV by the operator and the other lever arm 36 is manipulated with the other hand. It will be observed that the action of the latch mechanism 90' Y occurs simultaneously with the operation of the dies 24,

but the structureV of the latch mechanism is independent of the die structure and the links which -actuate the dies. Furthermore, the latch structure is relatively simple and inexpensive of construction and is disposed outside the mainV body portion of the tool whereV it may be easily maintained and, if desired, incorporated in existing tools. The latch structure may be embodied in existing tools, for example, by replacing the existing pivoted handle with a handle having its inner end portionV provided with a slot and latch member corresponding to the slot 96 and latch member 98 shown in the present embodiment, and by modifying the side plates (or the equivalent) of the Vexisting tool, or by replacing the plates, so as to provide the necessary abutment and cam surfaces with which the latch member may cooperate.v

Although one form of the invention has been shown and described by way of illustration, it is to be understood that it may be constructed in various other embodiments which come within the scope of the appended claims.

We claim:

1. In a tool adapted to form a joint between a metal Vseal and enclosed overlapping strap ends, the combination comprising a head, relatively movable parts mounted on said head and adapted to deform the seal and the strap` ends to forman interlocking joint, a lever on said head connected to said movable parts for operating said parts',

Vsaid lever beingV adapted to lbe-rnoved through a nstroke from a irstv position to-a second position to cause said parts to form said joint, said lever being thereupon adapted to be returned to said iirst position, a latch member movably mounted upon and carried solely by said lever, said latch member being movable with respect' to said lever between an active position and an inactive Y position, an obstructing surface on said head engaged by said latch member during return movement of said lever when said latch member is in said active position, said obstructing surface thereby preventing full return movement of said lever when said latch is in said active posit member in its inactive position during returning moveseal and enclosed overlapping strap ends, the combination comprising a head, relatively movable parts mounted on said head and adapted to deformy the seal and the strap ends to form an interlocking joint, a lever on said head connected to said movable parts for operating said par-ts, said lever being adapted to be moved through a stroke from a iirst position to a second position to cause said parts to form said joint, said lever being thereupon adapted to be returned to said rst position, a latch member movably mounted uponand carried by said lever exteriorly of said head, said latch member being movable with respect to said lever between an active position and an inactive position, an obstructing surface on the exterior of said head engaged by said latch member during return movement of said lever when said latch member is in said active position, said obstructing surface thereby preventing full return movement of said lever when said latch is in said active position, a cam surface on said head for camming said latch member from its active position toward its inactive position duringmovement of said lever into its said second position, and means on said head engaged by said latch member when said lever enters said second position for lodging said latch member in its inactive position to permit return movement of said lever. 3. The combination set forth in claim 2, including means on the exterior of said head engaged byrsaid latch member when said lever is returned to'said first position for dislodging said latch member from said inactive position. 4. iIn a tool adapted to form ajoint between a metal seal and enclosed overlapping strap ends, the combination comprising a head, relatively movable parts mounted on said head and adapted to deform the seal and the strap ends to form an interlocking joint, a lever on `said head connected to said movable parts for operating said parts, said lever being adapted to be moved through a stroke from a rst position to a second position to cause said parts to Vform said joint, said lever being thereupon adapted to be returned to said iirst position, said lever having an L-shaped slot therein, a latch member vcarried by said .lever within said slot, said latch member lbeing movable within said slot between an active position in one leg of said slot and lan inactive position inthe other leg of said slot, an obstructing surface on saidV head engaged by said latch member during return movement of said lever when said latch member is in said active position, said obstructing surface thereby preventing full return movement of said lever when said latch is in saidactive position, a camY surface on said head engaged by said latch member for camming saidlatch member from its active position toward its inactive position during movement of said lever into its said second position, and means on said lever for thereupon retaining said latch member in its inactive position in said other leg of said slot during returning movement of said lever.

References Cited in the tile of this patent UNITI-:D STATES PATENTS Hepler L Q-.. Oct. 14, 1958 

